"The impact of that collision resulted in the immediate death of the passenger Mr Muir," the police summary of facts says.
Croll-Davis crawled out of the wreck and walked to a nearby farmhouse "where he sought medical assistance for himself".
When police caught up with him, he denied being the driver.
The farm worker said Muir, 21, was driving and that he had been the front-seat passenger and that there had been "a number of other people" in the car who he did not know.
Croll-Davis earlier pleaded guilty at Christchurch District Court to a charge of driving with excess alcohol causing death. The charge carries a maximum penalty of 10 years' imprisonment. He also admitted three charges of driving while disqualified.
Today Judge Jane Farish sentenced him to three years, nine months' imprisonment. He was also disqualified from driving for five years.